New radio telescope in South Africa will study galaxy formation

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Country Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe MeerKAT, which stands for Karoo Array Telescope along with the Afrikaans word for “more,” is one of several precursor instruments for the SKA. The first phase of the SKA could begin in 2020 at a cost of €798 million. It would add another 133 dishes to MeerKAT, extending it across 150 kilometers, and place 130,000 smaller radio antennas across Australia—but only if member governments agree to fully fund the work. Months of delicate negotiations lie ahead. “In every country, people are having that discussion on what funding is available,” Falcke says.With MeerKAT’s 64 dishes now in place, engineers are learning how to process the data they gather. In a technique called interferometry, computers correlate the signals from pairs of dishes to build a much sharper image than a single dish could produce. For early science campaigns last year, 16 dishes were correlated. In March, the new supercomputer came online, and the team hopes to be fully operational by early next year. “It’s going to be a challenge,” Camilo says.MeerKAT’s dishes are smaller than the VLA’s, but having more of them puts it in “a sweet spot of sensitivity and resolution,” Camilo says. Its dishes are split into a densely packed core, which boosts sensitivity, and widely dispersed arms, which increase resolution. The VLA can opt for sensitivity or resolution, but not both at once—and only after the slow process of moving its 27 dishes into a different configuration.The combination makes MeerKAT ideal for mapping hydrogen, the fuel of star and galaxy formation. Because of a spontaneous transition in the atoms of neutral hydrogen, the gas constantly emits microwaves with a wavelength of 21 centimeters. Stretched to radio frequencies by the expansion of the universe, these photons land in the telescope’s main frequency band. It should have the sensitivity to map the faint signal to greater distances than before, and the resolution to see the gas moving in and around galaxies.MeerKAT will also watch for pulsars, dense and rapidly spinning stellar remnants. Their metronomic radio wave pulses serve as precise clocks that help astronomers study gravity in extreme conditions. “By finding new and exotic pulsars, MeerKAT can provide tests of physics,” says Philip Best of the University of Edinburgh. Falcke wants to get a better look at a highly magnetized pulsar discovered in 2013. He hopes it will shed light on the gravitational effects of the leviathan it orbits: the supermassive black hole at the center of the Milky Way.Other SKA precursors are taking shape. The Australian SKA Pathfinder (ASKAP) at the Murchison Radio-astronomy Observatory in Western Australia is testing a novel survey technology with its 36 12-meter dishes that could be used in a future phase of the SKA. Whereas a conventional radio dish has a single-element detector—the equivalent of a single pixel—the ASKAP’s detectors have 188 elements, which should help it quickly map galaxies across large areas of the sky.Nearby is the Murchison Widefield Array (MWA), an array of 2048 antennas, each about a meter across, that look like metallic spiders. Sensitive to lower frequencies than MeerKAT, the MWA can pick up the neutral hydrogen signal from as far back as 500 million years after the big bang, when the first stars and galaxies were lighting up the universe. Astronomers have been chasing the faint signal for years, and earlier this year, one group reported a tentative detection. “We’re really curious to see if it can be replicated,” says MWA Director Melanie Johnston-Hollitt of Curtin University in Perth, Australia.If the MWA doesn’t deliver a verdict, the SKA, with 130,000 similar antennas, almost certainly will. Although the MWA may detect the universe lighting up, the SKA intends to map out where it happened. By Daniel CleryJun. 19, 2018 , 1:00 PM SOUTH AFRICAN RADIO ASTRONOMY OBSERVATORY New radio telescope in South Africa will study galaxy formationcenter_img MeerKAT’s 64 dishes can study the way hydrogen gas moves around galaxies. Email Today, the Square Kilometre Array (SKA), a continent-spanning radio astronomy project, announced that Spain has come on board as the collaboration’s 11th member. That boost will help the sometimes-troubled project as, over the next year or so, it forms an international treaty organization and negotiates funding to start construction. Meanwhile, on the wide-open plains of the Karoo, a semiarid desert northeast of Cape Town, South Africa, part of the telescope is already in place in the shape of the newly completed MeerKAT, the largest and most powerful radio telescope in the Southern Hemisphere.The last of 64 13.5-meter dishes was installed late last year, and next month South African President Cyril Ramaphosa will officially open the facility. Spread across 8 kilometers, the dishes have a collecting area similar to that of the great workhorse of astrophysics, the Karl G. Jansky Very Large Array (VLA) near Socorro, New Mexico. But with new hardware designs and a powerful supercomputer to process data, the newcomer could have an edge on its 40-year-old northern cousin.“For certain studies, it will be the best” in the world, says Fernando Camilo, chief scientist of the South African Radio Astronomy Observatory in Cape Town, which operates MeerKAT. Sensitive across a wide swath of the radio spectrum, MeerKAT can study how hydrogen gas moves into galaxies to fuel star formation. With little experience, South Africa has “a major fantastic achievement,” says Heino Falcke of Radboud University in Nijmegen, the Netherlands.  Click to view the privacy policy. Required fields are indicated by an asterisk (*)last_img

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